Eocene prevolcanic sedimentary rocks
Basalt & volcanic. Paleogene, about 57 to 46 million years old. 5 crags on this site have their map point on it.
The map groups these named formations into this unit: Echo Park Alluvium, Telluride Conglomerate, Blanco Basin Formation.
What the map says
South-central: Arkosic sand and bouldery gravel of Echo Park Alluvium. Southwest: includes Telluride Conglomerate and Blanco Basin Fm (arkosic mudstone, sandstone, and conglomerate) Lithology: arkose, gravel, minor conglomerate, mudstone, sandstone.
1:500,000 sheet: Horton and others, 2017, U.S. Geological Survey Data Series 1052 (5 crags). A contact line at that scale is about 500 m wide on the ground.
Served by Macrostrat (CC BY 4.0). The wording is the map's own, quoted as a fact about the mapped unit, not about any one wall.